1. Field of the Invention
The present invention relates to a conductive paste for an inner electrode and a multilayer ceramic electronic component having the same, and more particularly, to a conductive paste for an inner electrode capable of forming an inner electrode with improved electrical characteristics and electrical connectivity and a multilayer ceramic electronic component having the same.
2. Description of the Related Art
Recently, as various electronic devices have been miniaturized, the demand for compact, multi-functional electronic components to be mounted in electronic devices has increased. In particular, as the stacking number is increased even in multilayer ceramic electronic components, such as a multilayer ceramic capacitor, or the like, the demand for thinness in individual layers thereof has increased.
In order to manufacture a multilayer ceramic electronic component such as a multilayer ceramic capacitor, or the like, a dielectric paste for a ceramic green sheet is first produced by mixing a ceramic powder, an organic binder such as an acrylic resin or a butyral resin, a plasticizer such as a phthalate ester, a glycol, adipic acid, a phosphate ester, or the like, and an organic solvent such as toluene, methyl ethyl ketone, acetone, or the like, and dispersing a mixture thereof.
Next, the ceramic green sheet is produced by applying the dielectric paste to a carrier film such as polyethylene terephthalate, polypropylene, or the like, by using a roller coater method, or the like, and firing the dielectric paste.
Thereafter, a conductive paste is produced by dissolving a conductive powder such as nickel powder in an organic binder and a solvent, and the inner electrode is then produced by printing the conductive paste on the ceramic green sheet by a screen printing method, or the like, and drying it.
Recently, in order to develop a super capacity MLCC having a layer thickness of 1 μm or less, the thickness of the inner electrodes thereof is also being slimmed. Since it is difficult to produce a thin film inner electrode by the screen printing method according to the related art, an attempt to form a thin film inner electrode through a gravure printing method has been conducted.
In the case of a fast printing method, such as the gravure printing method, the drying rate of a solvent therein is faster than that which is required for the screen printing method. That is, a boiling point of a solvent should be relatively low in order to dry a solvent at high speed.
In addition, the particle size of the nickel powder included in the conductive paste for an inner electrode used for the gravure printing is relatively small, such that the viscosity of the conductive paste is increased due to the increase in the specific surface area of the powder. Therefore, there is a need to develop a low-viscosity solvent since it is difficult to lower the viscosity of paste by using an existing solvent.